The invention relates to a method for wireless transmission of data onto a data carrier having a semiconductor circuit, in particular onto a chip card or IC card, and to a circuit array for implementation of said method.
In recent years, so-called chip cards or IC cards have come into increasing use, these being understood as data carriers that range from the familiar credit cards for cash dispensing machines, card telephones and other end units in communications technology, to identification cards for controlling access to sensitive-security zones. IC cards of this type contain a mechanically protected integrated semiconductor circuit with a non-volatile memory holding person-related and/or non-person-related data. A control logic is needed to read out the data stored and--if necessary in modified form--to read in the data. The circuit accommodated on the IC card does not generally have its own power supply; instead, the power necessary to read out the information is supplied without wires, for example inductively or capacitively, by the appropriate reader unit that reads out the stored information. At the same time, the data is transmitted without wires by suitable modulation of the voltage supply, so that the circuit can transmit data to the reader unit by, for example, field actuation.
The object underlying the present invention is to provide a method for wireless transmission of data onto a data carrier of the stated type that is easy to implement and requires little energy to operate. A further object is to provide a circuit array for implementation of this method.